如何在 TextView 文本中添加图像？

Question

我在 Google 上四处搜索，发现了一个与我类似的问题，即如何在 TextView 文本中包含图像，例如 "你好，我的名字是 [image] "，答案是这样的：

ImageSpan is = new ImageSpan(context, resId);
text.setSpan(is, index, index + strLength, 0);

我想知道这段代码，

1. 我应该在上下文中输入什么内容或做什么？
2. 我是否应该对text.setSpan() 做一些事情，例如导入或引用或留下文本？

如果有人能帮我分析一下，那将不胜感激。

Answer 1

试试这个..

    txtview.setCompoundDrawablesWithIntrinsicBounds(
                    R.drawable.image, 0, 0, 0);

也看到这个..http://developer.android.com/reference/android/widget/TextView.html

在 xml 文件中试试这个

    <TextView
        android:id="@+id/txtStatus"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:drawableLeft="@drawable/image"
        android:drawablePadding="5dp"
        android:maxLines="1"
        android:text="@string/name"/>

Answer 2

com/xyz/customandroid/ TextViewWithImages .java:

import java.util.regex.Matcher;
import java.util.regex.Pattern;

import android.content.Context;
import android.text.Spannable;
import android.text.style.ImageSpan;
import android.util.AttributeSet;
import android.util.Log;
import android.widget.TextView;

public class TextViewWithImages extends TextView {

    public TextViewWithImages(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }
    public TextViewWithImages(Context context, AttributeSet attrs) {
        super(context, attrs);
    }
    public TextViewWithImages(Context context) {
        super(context);
    }
    @Override
    public void setText(CharSequence text, BufferType type) {
        Spannable s = getTextWithImages(getContext(), text);
        super.setText(s, BufferType.SPANNABLE);
    }

    private static final Spannable.Factory spannableFactory = Spannable.Factory.getInstance();

    private static boolean addImages(Context context, Spannable spannable) {
        Pattern refImg = Pattern.compile("\\Q[img src=\\E([a-zA-Z0-9_]+?)\\Q/]\\E");
        boolean hasChanges = false;

        Matcher matcher = refImg.matcher(spannable);
    while (matcher.find()) {
        boolean set = true;
        for (ImageSpan span : spannable.getSpans(matcher.start(), matcher.end(), ImageSpan.class)) {
            if (spannable.getSpanStart(span) >= matcher.start()
             && spannable.getSpanEnd(span) <= matcher.end()
               ) {
                spannable.removeSpan(span);
            } else {
                set = false;
                break;
            }
        }
        String resname = spannable.subSequence(matcher.start(1), matcher.end(1)).toString().trim();
        int id = context.getResources().getIdentifier(resname, "drawable", context.getPackageName());
        if (set) {
            hasChanges = true;
            spannable.setSpan(  new ImageSpan(context, id),
                                matcher.start(),
                                matcher.end(),
                                Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                             );
        }
    }

        return hasChanges;
    }
    private static Spannable getTextWithImages(Context context, CharSequence text) {
        Spannable spannable = spannableFactory.newSpannable(text);
        addImages(context, spannable);
        return spannable;
    }
}

用途：

在 res/layout/mylayout.xml：

            <com.xyz.customandroid.TextViewWithImages
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textColor="#FFFFFF00"
                android:text="@string/can_try_again"
                android:textSize="12dip"
                style=...
                />

请注意，如果您将 TextViewWithImages.java 放置在 com/xyz/customandroid/ 以外的其他位置，则还必须更改包名称，com.xyz.customandroid 以上。

在 res/values/strings.xml：

<string name="can_try_again">Press [img src=ok16/] to accept or [img src=retry16/] to retry</string>

其中 ok16.png 和 retry16.png 是 res/drawable/ 文件夹中的图标

Answer 3

我尝试了许多不同的解决方案，这对我来说是最好的：

SpannableStringBuilder ssb = new SpannableStringBuilder(" Hello world!");
ssb.setSpan(new ImageSpan(context, R.drawable.image), 0, 1, Spannable.SPAN_INCLUSIVE_INCLUSIVE);
tv_text.setText(ssb, TextView.BufferType.SPANNABLE);

此代码使用最少的内存。

Answer 4

fun TextView.addImage(atText: String, @DrawableRes imgSrc: Int, imgWidth: Int, imgHeight: Int) {
    val ssb = SpannableStringBuilder(this.text)

    val drawable = ContextCompat.getDrawable(this.context, imgSrc) ?: return
    drawable.mutate()
    drawable.setBounds(0, 0,
            imgWidth,
            imgHeight)
    val start = text.indexOf(atText)
    ssb.setSpan(VerticalImageSpan(drawable), start, start + atText.length, Spannable.SPAN_INCLUSIVE_EXCLUSIVE)
    this.setText(ssb, TextView.BufferType.SPANNABLE)
}

VerticalImageSpan 类来自很好的答案 https://stackoverflow.com/a/38788432/5381331

使用

val textView = findViewById<TextView>(R.id.textview)
textView.setText("Send an [email-icon] to example@email.com.")
textView.addImage("[email-icon]", R.drawable.ic_email,
        resources.getDimensionPixelOffset(R.dimen.dp_30),
        resources.getDimensionPixelOffset(R.dimen.dp_30))

结果

注意
为什么VerticalImageSpan 类？
ImageSpan.ALIGN_CENTER 属性需要 API 29。
另外，经过测试，我看到ImageSpan.ALIGN_CENTER 仅在图像小于文本时才有效，如果图像大于文本则只有图像居中，文本不居中，它在图像底部对齐

Answer 5

此答案基于this excellent answer by 18446744073709551615。他们的解决方案虽然很有帮助，但不会使用周围的文本调整图像图标的大小。它也不会将图标颜色设置为周围文本的颜色。

以下解决方案采用白色方形图标，使其适合周围文本的大小和颜色。

public class TextViewWithImages extends TextView {

    private static final String DRAWABLE = "drawable";
    /**
     * Regex pattern that looks for embedded images of the format: [img src=imageName/]
     */
    public static final String PATTERN = "\\Q[img src=\\E([a-zA-Z0-9_]+?)\\Q/]\\E";

    public TextViewWithImages(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public TextViewWithImages(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public TextViewWithImages(Context context) {
        super(context);
    }

    @Override
    public void setText(CharSequence text, BufferType type) {
        final Spannable spannable = getTextWithImages(getContext(), text, getLineHeight(), getCurrentTextColor());
        super.setText(spannable, BufferType.SPANNABLE);
    }

    private static Spannable getTextWithImages(Context context, CharSequence text, int lineHeight, int colour) {
        final Spannable spannable = Spannable.Factory.getInstance().newSpannable(text);
        addImages(context, spannable, lineHeight, colour);
        return spannable;
    }

    private static boolean addImages(Context context, Spannable spannable, int lineHeight, int colour) {
        final Pattern refImg = Pattern.compile(PATTERN);
        boolean hasChanges = false;

        final Matcher matcher = refImg.matcher(spannable);
        while (matcher.find()) {
            boolean set = true;
            for (ImageSpan span : spannable.getSpans(matcher.start(), matcher.end(), ImageSpan.class)) {
                if (spannable.getSpanStart(span) >= matcher.start()
                        && spannable.getSpanEnd(span) <= matcher.end()) {
                    spannable.removeSpan(span);
                } else {
                    set = false;
                    break;
                }
            }
            final String resName = spannable.subSequence(matcher.start(1), matcher.end(1)).toString().trim();
            final int id = context.getResources().getIdentifier(resName, DRAWABLE, context.getPackageName());
            if (set) {
                hasChanges = true;
                spannable.setSpan(makeImageSpan(context, id, lineHeight, colour),
                        matcher.start(),
                        matcher.end(),
                        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                );
            }
        }
        return hasChanges;
    }

    /**
     * Create an ImageSpan for the given icon drawable. This also sets the image size and colour.
     * Works best with a white, square icon because of the colouring and resizing.
     *
     * @param context       The Android Context.
     * @param drawableResId A drawable resource Id.
     * @param size          The desired size (i.e. width and height) of the image icon in pixels.
     *                      Use the lineHeight of the TextView to make the image inline with the
     *                      surrounding text.
     * @param colour        The colour (careful: NOT a resource Id) to apply to the image.
     * @return An ImageSpan, aligned with the bottom of the text.
     */
    private static ImageSpan makeImageSpan(Context context, int drawableResId, int size, int colour) {
        final Drawable drawable = context.getResources().getDrawable(drawableResId);
        drawable.mutate();
        drawable.setColorFilter(colour, PorterDuff.Mode.MULTIPLY);
        drawable.setBounds(0, 0, size, size);
        return new ImageSpan(drawable, ImageSpan.ALIGN_BOTTOM);
    }

}

使用方法：

只需在文本中嵌入对所需图标的引用。文本是通过textView.setText(R.string.string_resource); 以编程方式设置还是在xml 中设置都没有关系。

要嵌入名为 example.png 的可绘制图标，请在文本中包含以下字符串：[img src=example/]。

例如，字符串资源可能如下所示：

<string name="string_resource">This [img src=example/] is an icon.</string>

Answer 6

这部分基于earlier answer above by @A Boschman。在那个解决方案中，我发现图像的输入大小极大地影响了makeImageSpan() 正确居中对齐图像的能力。此外，我发现该解决方案通过创建不必要的行间距来影响文本间距。

我发现BaseImageSpan（来自 Facebook 的 Fresco 库）做得特别好：

 /**
 * Create an ImageSpan for the given icon drawable. This also sets the image size. Works best
 * with a square icon because of the sizing
 *
 * @param context       The Android Context.
 * @param drawableResId A drawable resource Id.
 * @param size          The desired size (i.e. width and height) of the image icon in pixels.
 *                      Use the lineHeight of the TextView to make the image inline with the
 *                      surrounding text.
 * @return An ImageSpan, aligned with the bottom of the text.
 */
private static BetterImageSpan makeImageSpan(Context context, int drawableResId, int size) {
    final Drawable drawable = context.getResources().getDrawable(drawableResId);
    drawable.mutate();
    drawable.setBounds(0, 0, size, size);
    return new BetterImageSpan(drawable, BetterImageSpan.ALIGN_CENTER);
}

然后像往常一样将你的 betterImageSpan 实例提供给spannable.setSpan()

Answer 7

假设它是我们的 TextView

<TextView
    android:id="@+id/title"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerInParent="true"
    android:drawablePadding="4dp"
    android:drawableRight="@drawable/edit"
    android:text="Hello world"
    android:textSize="18dp" />

现在我们可以根据我们的要求添加以下任何一行

android:drawableLeft="@drawable/filename"
android:drawableRight="@drawable/filename"
android:drawableTop="@drawable/filename"
android:drawableBottom="@drawable/filename"

Answer 8

这可能对你有帮助

  SpannableStringBuilder ssBuilder;

        ssBuilder = new SpannableStringBuilder(" ");
        // working code ImageSpan image = new ImageSpan(textView.getContext(), R.drawable.image);
        Drawable image = ContextCompat.getDrawable(textView.getContext(), R.drawable.image);
        float scale = textView.getContext().getResources().getDisplayMetrics().density;
        int width = (int) (12 * scale + 0.5f);
        int height = (int) (18 * scale + 0.5f);
        image.setBounds(0, 0, width, height);
        ImageSpan imageSpan = new ImageSpan(image, ImageSpan.ALIGN_BASELINE);
        ssBuilder.setSpan(
                imageSpan, // Span to add
                0, // Start of the span (inclusive)
                1, // End of the span (exclusive)
                Spanned.SPAN_INCLUSIVE_EXCLUSIVE);// Do not extend the span when text add later

        ssBuilder.append(" " + text);
        ssBuilder = new SpannableStringBuilder(text);
        textView.setText(ssBuilder);